ST. PETERSBURG, Florida (AP) -- An arts columnist for a tabloid newspaper published by the St. Petersburg Times resigned after acknowledging that she posted several messages on a phony Web site mocking a county commissioner, the newspaper said.

Gina Vivinetto, who worked for tbt.., a free tabloid edition of the Times aimed at younger readers, resigned after posting comments on a phony MySpace.com site mocking Hillsborough County Commissioner Ronda Storms, who is known for her conservative stands on social issues.

"Sadly, Gina's actions irreparably compromised her credibility as a journalist for our company," Times executive editor Neil Brown said in a story published Friday.

Vivinetto had been with the Times since 1990, working as a copy clerk and then music critic. She joined the staff of tbt.. as an arts columnist last year.

Vivinetto could not be located for comment Friday. A phone number listed for her St. Petersburg, Florida, home had been disconnected.